1. Technical Field
This disclosure relates generally to a turbine engine and, more particularly, to mounts for connecting a gearbox to a turbine engine case.
2. Background Information
A turbine engine may include an accessory gearbox for driving one or more engine accessories. Examples of an engine accessory include a fuel pump, a scavenge pump, an electrical generator, an external deoiler and a hydraulic pump. The gearbox may also be connected to a starter, and drive a compressor section of the engine during start up. Three gearbox mounts typically connect the gearbox to the turbine engine case. The turbine engine case houses the engine core. A pair of radial mounts, for example, may extend radially inward from the gearbox to a first segment of the case, which houses the compressor section of the core. An axial mount may extend axially from the gearbox to a downstream second segment of the case, which is downstream of the first segment and houses a combustor section of the core.
Each of the gearbox mounts may include a fuse joint for reducing transmission of shock loads between the case and the gearbox. Such a fuse joint may prevent movement between the gearbox and the case during nominal flight conditions. However, the fuse joint may permit movement between the gearbox and the case during non-nominal flight conditions where the engine is subject to a shock load; e.g., where the engine is subject to heavy turbulence or a hard landing, the engine ingests a foreign object such as a bird, a rotor blade becomes unseated, etc. The radial mounts may each include a first type of fuse joint, and the axial mount may include a second type of fuse joint, or combination thereof.
The second segment of the case may be subject to the relatively high temperatures within the combustor section, which may cause this segment to thermally expand during engine operation. Such thermal expansion may subject the gearbox mounts and the gearbox to relatively high internal stresses. The expansion of the case, for example, may pull ends of the mounts that are connected to the case away from one another. The gearbox mounts and the gearbox therefore typically require greater safety margins and higher tolerances in order to withstand the additional internal stresses induced by the thermal expansion of the case. Such gearbox mount and gearbox over-engineering, however, may increase the complexity, cost and weight of the engine.
There is a need in the art for improved mounts for connecting a gearbox to a turbine engine case.